Achievable Rate And Encodinganalysis Of Relay Chan Nels With Generalized Feedback And Eavesdropper

With the rapid development of communication technology, modern mobile communications, satellite communications, communication networks, information networks are all in fact multi-user to multi-user channels.Among these information networks, how to ensure effective, reliable and secure transmission of information is of great importance.The earliest study of network channel is the multiple access channel.Later van der Meulen put forward relay channel in 1971 who also gave the inner bound of the channel capacity.Since then, research on the relay channel is getting more and more popular.Focused on the three-user memoryless relay channel,this paper mainly studys the achievable rate of relay channels with generalized feedback and the rate-equivocation region of relay channel with an addtional wire-tapper. The achievable rate of the relay channel is emphatically proposed and proved when both source node and destination node are duplex. In this channel model, an active cooperation between source node and relay node is enabled through using channel feedback in order to improve the communication efficiency. Consequently, a higher achievable rate is derived than the existed rate. Divide the information transmission rate into two parts and each part is sent from source node to destination node through help of the relay node using both decode-and-forward strategy and compress-and-forward strategy. The rate that sent by relay using compress-and-forward strategy is improved through source's feeback.While the other rate is sent by relay using decode-and-forward strategy taking advantage of destination's feeback.This thesis adds an eavesdropper into the relay channel with generalized feedback and studys the achievable secracy rate region of the new four-terminal model. The concept of rate equivocation is introduced to characterize the level of ignorance of the message at the wiretapper. The achievable secracy rate region is derived based on compress-and-forward strategy and decode-and-forward strategy of the relay-eavesdropper channel with generalized feedback.The paper shows that the achievable secracy rate can be improved by feedback.